The present invention relates to devices, such as sensors, using MEMS (Micro Electro Mechanical Systems) techniques, and methods for fabricating the same.
A technique called MEMS has recently seen progress in the art, which utilizes miniature processing techniques used in the fabrication of semiconductor LSI (Large Scale Integration) circuits. Using MEMS techniques, various miniature components, such as acceleration sensors, pressure sensors, and sonic sensors, have been proposed, and commercialization thereof has started.
Devices using MEMS techniques (hereinafter referred to as “MEMS devices”) include, as their major components, a substrate having a through hole, a diaphragm provided on the top surface of the substrate, a fixed film provided over the diaphragm with an air gap interposed therebetween and having a hole grouping composed of holes, and a supporting layer interposed between the diaphragm and the fixed film.
The configuration of a fixed film having a hole grouping composed of holes will be described below with reference to FIG. 23 (see, for example, Patent Document 1: Japanese Unexamined Patent Application Publication No. 2004-506394). FIG. 23 is a plan view illustrating the configuration of a fixed film in a conventional MEMS device.
As shown in FIG. 23, a hole grouping 201G, in which all holes 201 are arranged in a lattice pattern, is formed in a fixed film 200. When the center points of four adjacent holes 201 in the hole grouping 201G are connected, a square shape is formed in the lattice (see the dotted lines shown in FIG. 23).